Spring-jack for telephone-switchboards.



No. 853.370. PATENTED MAY 14, 1907. P. R. MOBBRTY & 5. B. GRAFT. SPRINGJACK PoR TELEPHONE SWITGHBoA RDS.

f/.f .w1/1.1.

@j I t' I w//w/.f

llwwmnllllmrf dada/215 UNITED STATES PATENT OFFICE.

FRAN K R. MCBERTY, OF EVANSTON, ANI) EDWARD B. CRAFT, OF CHICAGO,ILLINOIS, ASSIGNOR(1 TO WESTERN ELECTRIC COMPANY, OF (IIICAGO, ILLINOIS,A CORPORATION OF ILLINOIS.

SPRING-JACK FOR TELEPHONE-SWITCHBOARDS- Specification of Letters Patent.

Patented May 14, 1907.

Application filed December 10, 1904. Serial No. 236,278.

Be it known that we, FRANK R; MGBERTY and EDWARD B. CRAFT, citizens ofthe United States, residing at Evanston and Chicago, respectively, inthe 'county of Cook and State of Illinois, have invented a certain newand useful Improvement in Spring-Jacks for Telephone-Switchboards, ofwhich. the following is a full, clear, concise, and exact descri tion;

Our invention relates to a strip of springjacks for telephoneswitchboards, and its object is to provide an improved constructionwhich will be compact, light, strong, simple and -cheap to manufacture,and which will insure reliable switching action and proper insulation ofthe conducting parts.

In accordance with our invention, the tongue or connecting strip whichextends rearwardly from the test thimble or tube at the front of thejack, is bent a point between the front and rear supporting strips, .sothat the rear portion of said tongue is disposed on edge or in avertical plane, and is adapted to form a rigid backing piece lfor theline contact springs of the jack, which are also disposed on edgeparallel to-said tongue and preferably on either side thereof. A pair ofinsulated contact springs may be mounted on edge between the rearportionof the tongue and one of the line springs, to be operated whenfsaid linespring is flexed by the insertion of the plug in the jack. The contactsurfaces of the jack are thus disposed on edge to avoid accumulations ofdust thereon, while providing for an extremely compact arrangement ofthe partspwith. great strength and rigidity, and efficient insulation.

The verticallydisposed portion of the tongue or connecting strip beforereferred to is united with the test tube or thimble by means of an armor arms which may be bent to lie Iiat above or below the ends of theline springs and out of the pathl of the plug. Preferably the test tubeand its connecting strip are formed integrally. from a sheetrnetal blankor punching, one end of said blank being rolled to form the tube,l andthe rear portion of the connecting strip being united with the tube bytwo curved arms branching from the edges thereof, said arms being bentinto parallel planes at right anglcs to the plane of the rear portion.The

connecting strip thus forms a rigid connection or support between thefront and rear insulating supporting strips, which is particularlyadapted to withstand the stresses in all directions to which thespringjack will he subjected. Said connecting strip further forms asubstantial backing piece for the contact springs, whereby they may hemailitained in their proper positions relative to each other and to thetest tube. Such construction is furthermore especially adapted for"cut-'off jacks, where a switch contact is required in addition to theordinary line springs.

In the accompanying drawing, Figure l is a plan view of a strip ofspringjacks enibodying our invention; Fig. 2 is a front elevationshowing the openings adapted to receive the plugs, Fig. 3 shows an endview of the strip and a connecting plugin position to be insertedtherein g Fig. 4 is an isometric view showing the several parts of aspringjack ready for assembly; Fig. 5 is a detail view of the blank orpunching from which` the test tube and its connecting strip are formed.

The same. parts are indicated by similar letters f reference throughoutthe several figures of the drawing.

As shown, the strip of springjacks comprises front and rear supportingstrips m h of insulating material, and springj ackparts mounted therein.Each of the springjacks illustrated comprises .the usual line springs a,ZJ, a test tube or thiinble c and cut-off contacts e e. The testthiinble c is provided with a connecting strip or tongue extending tothe rear supporting strip, said tongue comprising a flat rear portion ddisposed in/a vertical plane in a groove in the rear supporting strip,and curved arms uniting said rear portion with the tube, said armsbranching from the upper and lower edges of the rear portion and beingturned over to lie in parallel planes at right angles to the plane ofthe rear portion, joining the rear edge of the test tube at the top andbottom thereof, respectively. The test tube with its connecting stripincluding the arms d d may be conveniently made from a Hat metalpunching of the form shown in Fig. 5, one end of the punching beingrolled up to form the tube, and the curved arms d d being lOO bent atthe edge ol the straight, portion d into l parallel planos at rightangles to the plane of said straight portion.

The real' portion of the strip d forms a rigid backing piece or trainefor the contact springs and their insulating strips going to build upthe spriugjaclr, These parts are assembled in parallel planes in atransverse slot or groove-in the `rear supporting strip, the linesprings projecting 'forward with their free ends iininediatel5T behindthe hole in the test t'liilnble, in position to engage the contacts olan inserted. plug. The line springs are disposed as shown on oppositesides ol the backing strip d, the movement of the springs being liinitedthereby. Insulating strips d2 d2 are provided on either side of thebacking strip, said strips extending to the front end of the straightportion d', as shown.

The line spring a, which in this instance is the long line spring, isarranged to operate a pair of contact springs e c', which, together withtheir insulating strips, lie between said line spring and the insulatingstrip d2 which is at theJ saine side of the backing piece d'. The springe carries an insulating spacer j which is adjusted to normali)T pressthe contact spring e against its lnate e, but when spring e is flexed,as by the insertion oi a connecting plug, such as the plug g shown inFig. 3, the contact spring e is left free to rnove by its own tensionout of engagement with its contact anvil e. These auxiliary contacts ee' may be used in accordance with the well known practice, to c-ontrolthe circuit of a subscribers line signal.

The rear endsV of the springs and tongue d of the jacks oi the strip,together with the several insulating stri as interposed between suchparts, are wedge edgewise into a transverse groove h in the rearinsulating strip or block h, which serves as a rigid support for saidsprings. It will be noted that the bacl ing pieces or tongues d of theseveral jacks serve as a support for the insulating block h, each tonguealso forming the frame or base upon which the parts oi' its own jack areassembled.@The springs and contacts of a jack being mounted on odge andparallel to one another, make a compact construction, and allow dustand. other 'foreign mattei' to 'liall between them instead ol"collecting on their surfaces and. interfering with the proper operationo'l" the device. Metal binding strips 'it' may be secured to the topand. bottoni of the strip it by screws, an insulating strip lc beinginterposed between the plate fi and the sup orting strip 7L over thegrooves therein as s iown, where/b5T the parts ol: the jack are heldagainst removal from said grooves.

We claiinzw 1. In a springjack, the combination with a pair of linesprings and a test piece, said test piece comprising a tube, rearwardlyextend,- ing tongue and arms uniting thein, said parts being stampedfreni a single piece of metal, the line springs being located onopposite sides of said tongue and insulated therefrom, of a pair ofcontact springs lyinV next to each other between the tongue and one ofsaid line springs, said springs being insulated from said tongue andline spring and arranged to be operated when the line spring is flexed,and an insulating block at the rear of the jack, in which said springsand tongue are mounted.

2. A sheet metal blank for a springjacl test thinible and connectingstrip, consisting of a front portion adapted to be rolled to forni thetube, a rear portion adapted to serve as a connector, and two arnisjoining said front and rear portions, said arms branching from saidfront portion at a diverging angle and recurving to join said rearportion.

In witness whereof, we hereunto subscribe our naines this 24th day of'October A. D., 1904.

. FRANK R. MUBERTY. EDWARD B. CRAFT.

Witnesses: A

FREDERICK l?. McIN'rosH, E. F. BEAUBIEN.

